Conventionally, in the electric system of automobiles or the like, multiple routed electric wires are laid through and held within a wire housing protector and secured at suitable locations in order to protect the electric wires from external members that might otherwise interfere with the electric wires and restrict the routing of the electric wires.
Incidentally, as described in JP H06-70415U (Patent Document 1) for example, such a wire housing protector is constituted by a trough-shaped protector body and a lid that covers the upper opening of the protector body. Once multiple electric wires are laid through the protector body, the lid is fixed to the protector body by a locking mechanism that protrudes from a sidewall of the protector body. In this way, the protector is capable of holding the multiple electric wires accommodated therein.
However, wire housing protectors having the foregoing conventional structure have an inherent problem in that, because the locking mechanism protrudes outward from a sidewall of the protector body, some of the capacity of the wire housing portion of the protector body is sacrificed so as to secure space for the locking mechanism. Especially in recent years, the demand for downsizing automobiles has been growing while the quantity of on-vehicle electrical equipment has also been increasing. Accordingly, there is a need to increase the housing space inside the protector body without enlarging the space necessary for mounting the wire housing protector. At times, conventionally structured wire housing protectors have been unable to meet this requirement sufficiently. In particular, there have been cases in which the lid could not easily interlock with the protector body because there were too many electric wires for the capacity of the wire housing protector.
Therefore, the applicant proposed, in JP 2014-82880A (Patent Document 2), a wire housing protector including a locking mechanism that is constituted by an elastic projecting piece that projects from an outer peripheral edge of a lid toward a protector body and an elastic projecting piece insertion hole that passes through the inside of a side wall of the protector body and opens in an upper surface, and in which an engagement protrusion provided at a leading end of the elastic projecting piece that has been inserted into the inside of the elastic projecting piece insertion hole engages with an engagement portion that projects from an inner surface of the elastic projecting piece insertion hole so as to prevent the lid from separating from the protector body. According to such a wire housing protector, because the locking mechanism is provided inside the side wall of the protector body, the side wall of the protector body can be extended to a maximum range of the space that is allowed to mount the wire housing protector, compared with a conventional structure in which the locking mechanism protrudes outward from the side wall of the protector body. Therefore, a dead space around the protector body that occurs due to the locking mechanism that protrudes outward from the side wall can be reduced, and the wire accommodating space in the protector body can be increased.
However, wire accommodation protectors having a structure in which the locking mechanism is provided inside the side wall of the protector body in this way suffer from an inherent problem. In particular, the opening area of the elastic projecting piece insertion hole that opens in the upper surface of the side wall of the protector body is inevitably made small, and therefore the task of inserting the elastic projecting piece into the elastic projecting piece insertion hole is difficult. Furthermore, the elastic projecting piece is inserted into the elastic projecting piece insertion hole while the elastic projecting piece is located inward of an outer peripheral surface of the protector body, and as a result, electric wires arranged in the vicinity of the upper surface of the side wall of the protector body are easily caught between the lid and the upper surface of the side wall of the protector body. Thus, further improvement is required.